<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./vue.js"></script>
    <style>
    body{
        font-family: Arial, Helvetica, sans-serif
    }
        .tab{
            width:600px;
            margin: 0 auto;
            border: 1px solid black;

        }
        .header{
        font-size:0;
        width:600px;
        border-bottom:1px solid #666;
        }
        .header a{
            display: inline-block;
            height: 40px;
            line-height: 40px;
            font-size: 16px;
            width:25%;
            text-align: center;
            color:#333;
            text-decoration: none;
        }
        .selected{
            background-color: #09f;
            color:#fff !important;
        }
        .show>div{
        border:1px solid #ccc;
        height:400px;
        padding-top:20px;
        }
    </style>
</head>
<body>
    <div id="app">
     <div class="tab">
         <div class="header">
             <a :class="{selected:currentPage==0}" href="#" @click.prevent="changePage(0)">HTML</a>
             <a :class="{selected:currentPage==1}" href="#" @click.prevent="changePage(1)">CSS</a>
             <a :class="{selected:currentPage==2}" href="#" @click.prevent="changePage(2)">JAVAScript</a>
             <a :class="{selected:currentPage==3}" href="#" @click.prevent="currentPage=3">Vue</a>
         </div>
         <div class="show">
             <div v-show="currentPage==0">HTML</div>
             <div v-show="currentPage==1">CSS</div>
             <div v-show="currentPage==2">JAVAScript</div>
             <div v-show="currentPage==3">vue</div>
         </div>
     </div>
    </div>
</body>
<script>
var vm=new Vue({
    el:"#app",
    data:{
    currentPage:0
    },
    methods:{
   changePage(page){
       this.currentPage=page
   }
    },
})
</script>
</html>